• 조명전기설비학회논문지
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• 제25권11호
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• pp.91-97
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• 2011

In Korea, characterized in most cases by limited area or high earth resistivity, it is likely to design narrow distances between grounding conductors, with a view to keeping ground resistance and touch voltage below the safety margin values. A new grounding method is suggested, making use of double meshes, to lower touch voltage in a confined area, since it is difficult to lay the plugs under the ground with narrow gaps between them on a limited site. For the presentation of a new model, the suggested grounding system has been analyzed and studied in ground resistance, touch voltage and step voltage, using IEEE Std. 80 calculations and computer simulations.

• 조명전기설비학회논문지
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• 제25권6호
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• pp.108-114
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• 2011

In order to mitigate the possible hazards from electric shock due to the touch and step voltages, the high resistivity material such as gravel is often spread on the earth's surface in substations. When the grounding electrode is installed in two-layer soil structures, the surface layer soil resistivity is different with the resistivity of the soil contacted with the grounding electrodes. The design of large-sized grounding systems is fundamentally based on assuring safety from dangerous voltages within a grounding grid area. The performance of the grounding system is evaluated by tolerable touch and step voltages. Since the floor surface conditions near equipment to be grounded are changed after a grounding system has been constructed, it may be difficult to determine the tolerable touch and step voltage criteria. In this paper, to propose an accurate and convenient method for evaluating the protective performance of grounding systems, the propriety of the method for evaluating the current flowing through the human body around on a counterpoise buried in two-layer soils is presented. As a result, it is reasonable that the grounding system performance would be evaluated by measuring and analyzing the current flowing through the human body based on dangerous voltages such as the touch or step voltages and the contact resistance between the ground surface and feet.

• Transactions on Electrical and Electronic Materials
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• 제12권4호
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• pp.152-155
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• 2011

This paper presents a comparative analysis on step and the touch voltages generated by either a sine and a ring wave voltage generator; this analysis was done as a basic study in order to develop a small and lightweight ground meter. A ring wave generator using pulsed power technology was fabricated; an experimental grounding system specified in Institute of Electrical and Electronics Engineers standards 80 and 81 was installed. The step and the touch voltages, which were measured using comparable a sine and a ring waves in terms of magnitude and frequency, were equal. Using pulsed power technology, the weight of the fabricated ring wave generator could be reduced to one-fifth of that of a sine wave generator. Consequently, if a ground meter adopts the ring wave instead of a sine wave, it will be possible to reduce the weight of a ground meter and improve the efficiency of measurement.

• 한국전기전자재료학회논문지
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• 제24권3호
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• pp.250-255
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• 2011

This paper dealt with the design, fabrication and application of a risk voltage measurement system (RVMS) which analyzes the step and touch voltages in electrical grounding systems. The RVMS supply 300 V and 1.4 A in ranges from 40 Hz to 1 kHz as the test power source. A DAQ module having resolution of 400 kS/s and 16 bit is equipped with 7 inputs for measuring voltage and current. Also, a noise elimination algorithm of digital filter was applied to reduce the measurement error caused by external noises as a commercial frequency current. The performance of the RVMS was evaluated by measurement of the step and touch voltage according to the IEEE standard 80 and 81 in a grounding system with a 10 m counterpoise. The result showed that the RVMS analyzes the risk voltage with the error below 5%.

• 조명전기설비학회논문지
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• 제21권8호
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• pp.113-120
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• 2007

본 논문은 TN-C-S계통에서 중성선 겸용 보호도체(PEN도체)의 단선고장시 감전의 위험성 및 보호대책에 관한 것으로 PEN도체의 단선고장시 노출도전성 부분의 접촉전압을 줄이기 위하여 전원측 접지저항과 수용가 추가접지 저항에 따른 PEN도체 단선시 노출도전성 부분에 나타나는 접촉전압을 실험적으로 조사하였다. 그 결과 TN-C-S 계통으로 공급되는 설비에 대하여 등전위본딩은 중요한 요건이다. 수용가의 인입구에 추가접지를 하는 것은 PEN 도체의 단선시 노출도전성 부분에 나타나는 접촉전압을 저감시키는 방법 중의 하나이다. 접촉전압을 안전전압 50[V]이하로 제한하는데 필요한 추가접지의 접지저항은 부하용량과 고장회로정수에 의하여 정해진다. 또한 부족전압계전기는 TN-C-S계통에서 PEN도체의 단선고장을 검출할 수 있는 적절한 해결방안이 될 수 있다.

• 조명전기설비학회논문지
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• 제22권4호
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• pp.68-77
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• 2008

국내 접지설계시 가장 널리 사용되는 것은 IEEE Std. 80 위험전압 계산식이나 국내 접지설계 환경의 적정성 여부는 검토되지 않고 있다. 따라서, 본 논문에서는 IEEE Std. 80 접촉전압 계산식의 적용한계를 검토하고 그 문제점을 극복하기 위해 IEEE Std. 80 접촉전압값과 컴퓨터 모의실험값을 비교하여 접촉전압 계산식의 보정계수 $K_a$를 유도하였다. 또한, 유도된 모델 중 Logistic 모델 형식의 보정계수를 적용할 경우 최대 오차율이 10[%]미만인 것을 검증함으로써 고가의 프로그램을 사용하지 않고도 안전하고 경제적인 접지설계를 할 수 있는 방법을 제시하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권3호
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• pp.380-386
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• 2016

This paper presents a compact and low-power on-chip touch sensor and readout circuit using shunt proximity touch sensor and its design scheme. In the proposed touch sensor readout circuit, the touch panel condition depending on the proximity of the finger is directly converted into the corresponding voltage level without additional signal conditioning procedures. Furthermore, the additional circuitry including the comparator and the flip-flop does not consume any static current, which leads to a low-power design scheme. A new prototype touch sensor readout integrated circuit was fabricated using complementally metal oxide silicon (CMOS) $0.18{\mu}m$ technology with core area of $0.032mm^2$ and total current of $125{\mu}A$. Our measurement result shows that an actual 10.4 inches capacitive type touch screen panel (TSP) can detect the finger size from 0 to 1.52 mm, sharply.

• 조명전기설비학회논문지
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• 제26권6호
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• pp.81-86
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• 2012

This paper describes the analysis technique of risk voltage around grounding electrode by new touch and step voltage measurement methods. We have analyzed three techniques for risk voltage measurement, such as footprint-electrode method, test-probe method, and simulated-personnel method. We have selected test-probe method considering applicability of site. In order to reduce error related to the location of the auxiliary electrode, we propose a new approach to perform risk voltage measurement with minimum errors and short auxiliary electrode distances. Field tests were carried out at a grounding grid. It can be concluded that the proposed method will be satisfactory for risk voltage measurement.

• 전기학회논문지
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• 제56권10호
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• pp.1796-1801
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• 2007

This paper presents electric potential rise on the surface of the earth due to ground currents. It is the aim of this paper to propose fundamental data relevant to the earth surface potentials depending on the soil structures. The earth potential rise, touch and step voltages in the immediate vicinity of the ground rod of a distribution pole were measured and analyzed. The results described in this paper are based on laboratory measurements which were intended to simulate conditions existing in actual installations. As a result, the earth surface potential rise, touch and step voltages strongly depend on the soil structure. The highest earth surface potential occurred in the vicinity of the top of ground rod. When the ground rod was installed in the distance range of $1{\sim}1.5\;m$ from distribution pole, the highest touch voltages appeared near the place of 1 m on the straight line connecting the distribution pole to ground rod.

• 한국정보통신학회논문지
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• 제16권2호
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• pp.319-324
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• 2012

본 논문에서는 개선된 charge pump 회로를 이용하여 구성한 2-dimensional 터치스크린 패널 드라이버를 소개한다. 개선된 전정 센싱 회로는 charge pump 회로의 중간노드 전하 축적을 제거하여 출력 전압 표류 현상을 효과적으로 없앤다. 터치 패널 드라이버는 터치를 감지하는 아날로그 센싱 부분과 감지된 신호를 처리하는 디지털 신호 처리 부분으로 이루어진다. 제안된 터치스크린 드라이버의 동작을 확인하기 위하여 혼성 모드로 회로를 구성하고 Cadence Spectre를 이용하여 그 동작을 검증하였다. 디지털 회로 부분은 Verilog-A로 모델링하여 아날로그 회로와 인터페이스가 가능하게 하여 전체 회로 동작을 검증함으로써 혼성모드 회로 동작의 신뢰성을 확보하였고 시뮬레이션 시간을 단축할 수 있었다. 시뮬레이션 결과 개선된 전정 센싱 회로를 이용한 제안된 구조의 터치 패널 드라이버의 안정적인 동작을 확인하였다.